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cytherm.c
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1 /* -*- linux-c -*-
2  * Cypress USB Thermometer driver
3  *
4  * Copyright (c) 2004 Erik Rigtorp <[email protected]> <[email protected]>
5  *
6  * This driver works with Elektor magazine USB Interface as published in
7  * issue #291. It should also work with the original starter kit/demo board
8  * from Cypress.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation, version 2.
13  *
14  */
15 
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/init.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/usb.h>
23 
24 #define DRIVER_VERSION "v1.0"
25 #define DRIVER_AUTHOR "Erik Rigtorp"
26 #define DRIVER_DESC "Cypress USB Thermometer driver"
27 
28 #define USB_SKEL_VENDOR_ID 0x04b4
29 #define USB_SKEL_PRODUCT_ID 0x0002
30 
31 static const struct usb_device_id id_table[] = {
32  { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
33  { }
34 };
35 MODULE_DEVICE_TABLE (usb, id_table);
36 
37 /* Structure to hold all of our device specific stuff */
38 struct usb_cytherm {
39  struct usb_device *udev; /* save off the usb device pointer */
40  struct usb_interface *interface; /* the interface for this device */
42 };
43 
44 
45 /* local function prototypes */
46 static int cytherm_probe(struct usb_interface *interface,
47  const struct usb_device_id *id);
48 static void cytherm_disconnect(struct usb_interface *interface);
49 
50 
51 /* usb specific object needed to register this driver with the usb subsystem */
52 static struct usb_driver cytherm_driver = {
53  .name = "cytherm",
54  .probe = cytherm_probe,
55  .disconnect = cytherm_disconnect,
56  .id_table = id_table,
57 };
58 
59 /* Vendor requests */
60 /* They all operate on one byte at a time */
61 #define PING 0x00
62 #define READ_ROM 0x01 /* Reads form ROM, value = address */
63 #define READ_RAM 0x02 /* Reads form RAM, value = address */
64 #define WRITE_RAM 0x03 /* Write to RAM, value = address, index = data */
65 #define READ_PORT 0x04 /* Reads from port, value = address */
66 #define WRITE_PORT 0x05 /* Write to port, value = address, index = data */
67 
68 
69 /* Send a vendor command to device */
70 static int vendor_command(struct usb_device *dev, unsigned char request,
71  unsigned char value, unsigned char index,
72  void *buf, int size)
73 {
74  return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
75  request,
77  value,
78  index, buf, size,
79  USB_CTRL_GET_TIMEOUT);
80 }
81 
82 
83 
84 #define BRIGHTNESS 0x2c /* RAM location for brightness value */
85 #define BRIGHTNESS_SEM 0x2b /* RAM location for brightness semaphore */
86 
87 static ssize_t show_brightness(struct device *dev, struct device_attribute *attr, char *buf)
88 {
89  struct usb_interface *intf = to_usb_interface(dev);
90  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
91 
92  return sprintf(buf, "%i", cytherm->brightness);
93 }
94 
95 static ssize_t set_brightness(struct device *dev, struct device_attribute *attr, const char *buf,
96  size_t count)
97 {
98  struct usb_interface *intf = to_usb_interface(dev);
99  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
100 
101  unsigned char *buffer;
102  int retval;
103 
104  buffer = kmalloc(8, GFP_KERNEL);
105  if (!buffer) {
106  dev_err(&cytherm->udev->dev, "out of memory\n");
107  return 0;
108  }
109 
110  cytherm->brightness = simple_strtoul(buf, NULL, 10);
111 
112  if (cytherm->brightness > 0xFF)
113  cytherm->brightness = 0xFF;
114  else if (cytherm->brightness < 0)
115  cytherm->brightness = 0;
116 
117  /* Set brightness */
118  retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS,
119  cytherm->brightness, buffer, 8);
120  if (retval)
121  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
122  /* Inform µC that we have changed the brightness setting */
123  retval = vendor_command(cytherm->udev, WRITE_RAM, BRIGHTNESS_SEM,
124  0x01, buffer, 8);
125  if (retval)
126  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
127 
128  kfree(buffer);
129 
130  return count;
131 }
132 
134  show_brightness, set_brightness);
135 
136 
137 #define TEMP 0x33 /* RAM location for temperature */
138 #define SIGN 0x34 /* RAM location for temperature sign */
139 
140 static ssize_t show_temp(struct device *dev, struct device_attribute *attr, char *buf)
141 {
142 
143  struct usb_interface *intf = to_usb_interface(dev);
144  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
145 
146  int retval;
147  unsigned char *buffer;
148 
149  int temp, sign;
150 
151  buffer = kmalloc(8, GFP_KERNEL);
152  if (!buffer) {
153  dev_err(&cytherm->udev->dev, "out of memory\n");
154  return 0;
155  }
156 
157  /* read temperature */
158  retval = vendor_command(cytherm->udev, READ_RAM, TEMP, 0, buffer, 8);
159  if (retval)
160  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
161  temp = buffer[1];
162 
163  /* read sign */
164  retval = vendor_command(cytherm->udev, READ_RAM, SIGN, 0, buffer, 8);
165  if (retval)
166  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
167  sign = buffer[1];
168 
169  kfree(buffer);
170 
171  return sprintf(buf, "%c%i.%i", sign ? '-' : '+', temp >> 1,
172  5*(temp - ((temp >> 1) << 1)));
173 }
174 
175 
176 static ssize_t set_temp(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
177 {
178  return count;
179 }
180 
182 
183 
184 #define BUTTON 0x7a
185 
186 static ssize_t show_button(struct device *dev, struct device_attribute *attr, char *buf)
187 {
188 
189  struct usb_interface *intf = to_usb_interface(dev);
190  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
191 
192  int retval;
193  unsigned char *buffer;
194 
195  buffer = kmalloc(8, GFP_KERNEL);
196  if (!buffer) {
197  dev_err(&cytherm->udev->dev, "out of memory\n");
198  return 0;
199  }
200 
201  /* check button */
202  retval = vendor_command(cytherm->udev, READ_RAM, BUTTON, 0, buffer, 8);
203  if (retval)
204  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
205 
206  retval = buffer[1];
207 
208  kfree(buffer);
209 
210  if (retval)
211  return sprintf(buf, "1");
212  else
213  return sprintf(buf, "0");
214 }
215 
216 
217 static ssize_t set_button(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
218 {
219  return count;
220 }
221 
222 static DEVICE_ATTR(button, S_IRUGO, show_button, set_button);
223 
224 
225 static ssize_t show_port0(struct device *dev, struct device_attribute *attr, char *buf)
226 {
227  struct usb_interface *intf = to_usb_interface(dev);
228  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
229 
230  int retval;
231  unsigned char *buffer;
232 
233  buffer = kmalloc(8, GFP_KERNEL);
234  if (!buffer) {
235  dev_err(&cytherm->udev->dev, "out of memory\n");
236  return 0;
237  }
238 
239  retval = vendor_command(cytherm->udev, READ_PORT, 0, 0, buffer, 8);
240  if (retval)
241  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
242 
243  retval = buffer[1];
244 
245  kfree(buffer);
246 
247  return sprintf(buf, "%d", retval);
248 }
249 
250 
251 static ssize_t set_port0(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
252 {
253  struct usb_interface *intf = to_usb_interface(dev);
254  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
255 
256  unsigned char *buffer;
257  int retval;
258  int tmp;
259 
260  buffer = kmalloc(8, GFP_KERNEL);
261  if (!buffer) {
262  dev_err(&cytherm->udev->dev, "out of memory\n");
263  return 0;
264  }
265 
266  tmp = simple_strtoul(buf, NULL, 10);
267 
268  if (tmp > 0xFF)
269  tmp = 0xFF;
270  else if (tmp < 0)
271  tmp = 0;
272 
273  retval = vendor_command(cytherm->udev, WRITE_PORT, 0,
274  tmp, buffer, 8);
275  if (retval)
276  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
277 
278  kfree(buffer);
279 
280  return count;
281 }
282 
283 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR | S_IWGRP, show_port0, set_port0);
284 
285 static ssize_t show_port1(struct device *dev, struct device_attribute *attr, char *buf)
286 {
287  struct usb_interface *intf = to_usb_interface(dev);
288  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
289 
290  int retval;
291  unsigned char *buffer;
292 
293  buffer = kmalloc(8, GFP_KERNEL);
294  if (!buffer) {
295  dev_err(&cytherm->udev->dev, "out of memory\n");
296  return 0;
297  }
298 
299  retval = vendor_command(cytherm->udev, READ_PORT, 1, 0, buffer, 8);
300  if (retval)
301  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
302 
303  retval = buffer[1];
304 
305  kfree(buffer);
306 
307  return sprintf(buf, "%d", retval);
308 }
309 
310 
311 static ssize_t set_port1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
312 {
313  struct usb_interface *intf = to_usb_interface(dev);
314  struct usb_cytherm *cytherm = usb_get_intfdata(intf);
315 
316  unsigned char *buffer;
317  int retval;
318  int tmp;
319 
320  buffer = kmalloc(8, GFP_KERNEL);
321  if (!buffer) {
322  dev_err(&cytherm->udev->dev, "out of memory\n");
323  return 0;
324  }
325 
326  tmp = simple_strtoul(buf, NULL, 10);
327 
328  if (tmp > 0xFF)
329  tmp = 0xFF;
330  else if (tmp < 0)
331  tmp = 0;
332 
333  retval = vendor_command(cytherm->udev, WRITE_PORT, 1,
334  tmp, buffer, 8);
335  if (retval)
336  dev_dbg(&cytherm->udev->dev, "retval = %d\n", retval);
337 
338  kfree(buffer);
339 
340  return count;
341 }
342 
343 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR | S_IWGRP, show_port1, set_port1);
344 
345 
346 
347 static int cytherm_probe(struct usb_interface *interface,
348  const struct usb_device_id *id)
349 {
350  struct usb_device *udev = interface_to_usbdev(interface);
351  struct usb_cytherm *dev = NULL;
352  int retval = -ENOMEM;
353 
354  dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
355  if (dev == NULL) {
356  dev_err (&interface->dev, "Out of memory\n");
357  goto error_mem;
358  }
359 
360  dev->udev = usb_get_dev(udev);
361 
362  usb_set_intfdata (interface, dev);
363 
364  dev->brightness = 0xFF;
365 
366  retval = device_create_file(&interface->dev, &dev_attr_brightness);
367  if (retval)
368  goto error;
369  retval = device_create_file(&interface->dev, &dev_attr_temp);
370  if (retval)
371  goto error;
372  retval = device_create_file(&interface->dev, &dev_attr_button);
373  if (retval)
374  goto error;
375  retval = device_create_file(&interface->dev, &dev_attr_port0);
376  if (retval)
377  goto error;
378  retval = device_create_file(&interface->dev, &dev_attr_port1);
379  if (retval)
380  goto error;
381 
382  dev_info (&interface->dev,
383  "Cypress thermometer device now attached\n");
384  return 0;
385 error:
386  device_remove_file(&interface->dev, &dev_attr_brightness);
387  device_remove_file(&interface->dev, &dev_attr_temp);
388  device_remove_file(&interface->dev, &dev_attr_button);
389  device_remove_file(&interface->dev, &dev_attr_port0);
390  device_remove_file(&interface->dev, &dev_attr_port1);
391  usb_set_intfdata (interface, NULL);
392  usb_put_dev(dev->udev);
393  kfree(dev);
394 error_mem:
395  return retval;
396 }
397 
398 static void cytherm_disconnect(struct usb_interface *interface)
399 {
400  struct usb_cytherm *dev;
401 
402  dev = usb_get_intfdata (interface);
403 
404  device_remove_file(&interface->dev, &dev_attr_brightness);
405  device_remove_file(&interface->dev, &dev_attr_temp);
406  device_remove_file(&interface->dev, &dev_attr_button);
407  device_remove_file(&interface->dev, &dev_attr_port0);
408  device_remove_file(&interface->dev, &dev_attr_port1);
409 
410  /* first remove the files, then NULL the pointer */
411  usb_set_intfdata (interface, NULL);
412 
413  usb_put_dev(dev->udev);
414 
415  kfree(dev);
416 
417  dev_info(&interface->dev, "Cypress thermometer now disconnected\n");
418 }
419 
420 module_usb_driver(cytherm_driver);
421 
424 MODULE_LICENSE("GPL");